Capsule filling machine and method for producing hard gelatin capsules

ABSTRACT

A capsule filling machine ( 100 ) for the production of hard gelatin capsules (C) of the type with lid ( 3 ) and body ( 2 ) containing a quantity ( 1 ) of pharmaceutical material comprises a rotary turret or carousel ( 15 ) which defines at least one capsule (C) handling line (L) and on which the following are positioned, one after the other: at least one station ( 6 ) for feeding empty capsules (C); at least one opening station ( 20 ) where the capsule bodies ( 2 ) are separated from the lids ( 3 ) to form two separate rows of capsule bodies ( 2 ) and lids ( 3 ); at least one station ( 7 ) for feeding and dosing the quantities ( 1 ) of pharmaceutical material to be filled into the capsule bodies ( 2 ); and at least one station ( 8 ) for closing the capsules (C) by placing a lid ( 3 ) over each respective body ( 2 ); the machine ( 100 ) also comprises means ( 9 ) for detecting and volumetrically checking the quantity ( 1 ) of pharmaceutical material filled into each capsule body ( 2 ), the detecting and checking means ( 9 ) comprise transducer means ( 5 ) for measuring the volume of said quantities ( 1 ) before they are filled into the capsule bodies ( 2 ).

CROSS-REFERENCE TO RELATED APPLICATION

This application is a National Stage entry of International ApplicationNumber PCT/IB2005/001398, filed May 9, 2005. The disclosure of the priorapplication is hereby incorporated herein in its entirety by reference.

TECHNICAL FIELD

The present invention relates to a capsule filling machine and methodfor producing hard gelatin capsules.

In particular, the present invention can be advantageously applied tothe production of hard gelatin capsules of the type with lid and bodywhich contain pharmaceutical material in solid form, such as pellets,microtablets and the like, which the present specification expresslyrefers to but without thereby restricting the scope of the invention.

BACKGROUND ART

A modern capsule filling machine for making hard gelatin capsulesnormally comprises a rotary turret or carousel equipped with a pluralityof operating stations for processing the capsules according to astandard method consisting of the following sequence of basic steps:opening the closed empty capsules at a station where the capsule bodiesare separated from the lids to form two separate rows of bodies andlids; filling a predetermined quantity of pharmaceutical material insolid form into each capsule body at a dosing station; and closing eachfilled capsule by applying a lid to the respective body.

Once closed, the capsules are expelled from the carousel of the fillingmachine and fed into an appropriate container.

The capsules made in filling machines of this type also have to beweighed to ensure that they have been filled correctly. At present, thisis done according to two different methods.

In a first method, the final weight of the capsules is checkedstatistically, that is to say, by taking samples of closed filledcapsules and weighing them on electronic checkweighers connected to thecentral unit that controls and sets the quantities of solidpharmaceutical material to be filled into the capsule bodies.

Although this method is effective, it has an inherent disadvantagelinked precisely to the statistical nature of the checkweighing system.Thus, if sample capsules failing outside the predetermined weight rangesare detected, a certain amount of time passes before the system correctsthe dose of pharmaceutical material. This “time lag” means there isalways the risk that a certain number of unchecked capsules of incorrectweight will be produced.

In an alternative method, the level of the pharmaceutical material dosefilled into each capsule body is individually checked before the lidsare applied to the respective bodies.

The pharmaceutical material level, from which the weight of each capsuleis calculated, is checked using optical sensors.

These optical sensors, however, are difficult to control, involvecomplicated calibrating procedures and, above all, are not alwayscapable of providing satisfactory readings of the level of solidmaterial in the capsule bodies, with the result that many capsulespassed by the sensors are in fact incorrectly filled, that is to say,are subsequently found to be faulty in weight.

The present invention therefore has for an aim to overcome the abovementioned disadvantages.

In particular, the present invention has for an aim to provide a capsulefilling machine where the weight of all the capsules is checked in thefilling process during a rapid, accurate operating step performed usinga simple and effective instrument of mechanical type.

DISCLOSURE OF THE INVENTION

This invention accordingly provides a capsule filling machine for theproduction of hard gelatin capsules of the type with lid and bodycontaining a quantity of pharmaceutical material, the machine comprisinga rotary turret or carousel which defines at least one capsule handlingline and on which the following are positioned, one after the other: atleast one station for feeding empty capsules; at least one openingstation where the capsule bodies are separated from the lids to form twoseparate rows of capsule bodies and lids; at least one station forfeeding and dosing the quantities of pharmaceutical material to befilled into the capsule bodies; and at least one station for closing thecapsules by placing a lid over each respective body; the machine beingcharacterised in that it further comprises means for detecting andvolumetrically checking the quantity of pharmaceutical material filledinto each capsule body, said detecting and checking means comprisingtransducer means for measuring the volume of said quantities before theyare inserted into the capsule bodies.

This invention also relates to a method for producing hard gelatincapsules of the type with lid and body containing a quantity ofpharmaceutical material, the method comprising the steps of feedingclosed empty capsules to an opening station where the capsule bodies areseparated from the lids to form two separate rows of capsule bodies andlids; filling each capsule body with a predetermined quantity ofpharmaceutical material; and closing the filled capsule bodies byplacing the lids over the respective bodies; the method beingcharacterised in that it further comprises a step of detecting andvolumetrically checking the quantity of pharmaceutical material, thisstep being performed before each quantity of pharmaceutical material isinserted into the respective capsule body.

BRIEF DESCRIPTION OF THE DRAWINGS

The technical characteristics of the invention, with reference to theabove aims, are clearly described in the claims below and its advantagesare apparent from the detailed description which follows, with referenceto the accompanying drawings which illustrate a preferred embodiment ofthe invention provided merely by way of example without restricting thescope of the inventive concept, and in which:

FIG. 1 is a schematic top plan view, with some parts in cross sectionand others cut away for clarity, of a capsule filling machine accordingto the present invention, for making hard gelatin capsules;

FIG. 2 is a schematic front view, with some parts in cross section, of afirst detail P1 of the machine of FIG. 1, showing an operating stationthat doses the solid pharmaceutical material;

FIG. 3 is a schematic front view, with some parts in cross section, of asecond detail P2 of the capsule filling machine of FIG. 1, showing asecond operating station forming part of the machine; and

FIG. 4 is a schematic front view, with some parts in cross section, of athird detail P3 of the capsule filling machine of FIG. 1, showing athird operating station forming part of the machine according to thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

With reference to the accompanying drawings, the numeral 100 in FIG. 1denotes in its entirety a capsule filling machine for making capsules Cfilled with pharmaceutical material in solid form, preferablymicrotablets or pellets.

The capsules C are of the known type with lid and body, that is to say,each comprises a body 2 for receiving the pharmaceutical material and alid 3 which is placed over the body 2 in such a way as to close it(FIGS. 2, 3 and 4).

As illustrated in FIG. 1, the capsule filling machine 100 is of the typecomprising a rotary turret or carousel 15 which defines at least onecircular line L for handling the capsules C and which is equipped with aplurality of operating stations for processing the capsules Cthemselves. Preferably, as shown in the accompanying drawings, themachine 100 has two adjacent and identical capsule C handling lines Lbut for brevity of description reference will be made to only onehandling line L.

More specifically, the aforementioned operating stations comprise: atleast one station 6 for feeding the capsule bodies 2 and lids 3 in aclosed, empty configuration, that is to say, joined to each other butempty; an opening station 20 where the capsule bodies 2 are separatedfrom the lids 3 to form two separate rows of capsule lids 3 and bodies2; a station 7 for feeding and dosing the pharmaceutical material to befilled into the capsule bodies 2; a station 8 for closing the capsules Cby placing a lid 3 over each respective body 2; and, lastly, an outfeedstation 22 for unloading the capsules C made in this way into acontainer (of known type and not illustrated).

As shown in FIGS. 2, 3 and 4, the machine 100 also comprises, at thedosing station 7, means 9 for detecting and volumetrically checking thequantity 1 of pharmaceutical material to be filled into each capsulebody 2.

The checking means 9 comprise at least one uniformly distributed seriesof compartments or chambers 4 for holding respective quantities 1 ofpharmaceutical material (FIGS. 2 and 4 show identical and adjacentseries of chambers 4).

As illustrated in FIGS. 2 and 4, the chambers 4 are made in a dosechecking disk 11 associated with the carousel 15 that rotates along theaforementioned circular line L. Each chamber 4 is cylindrical in shape,with a height H and a uniform diameter D, and has an opening 4 a at thetop and an opening 4 b at the bottom, the latter being designed to beclosed by suitable contact elements 10 of the reciprocating plate typemoving towards and away from the chamber 4 itself (arrow F, FIGS. 3 and4).

Again with reference FIGS. 2, 3 and 4, each chamber 4 houses a lineartransducer element 5 (FIG. 3) (also known by the term Linear VariableDetector Transducer or LVDT) which forms an integral part of thechecking means 9.

The linear transducer 5 is designed to detect the height H1 of thequantity 1 of pharmaceutical material inside the chamber 4 (FIG. 2) at achecking station 12 of the machine 100.

At a constructional level, the checking station 12 is located betweenthe dosing station 7 and the closing station 8 on the handling line Land is equipped with the linear transducers 5, each of which comprises asliding detector element 13 driven vertically by actuating means 14(illustrated as a block since they are of well known type) and designedto measure the height H1 reached by the quantity 1 of pharmaceuticalmaterial in the respective dosing chamber 4 (FIG. 3).

Each linear transducer 5 is in turn connected to a control andprocessing unit 18 designed to receive from the linear transducer 5itself a signal S proportional to the H1 of the material detected in therespective chamber 4. During use, the control unit 18 (also illustratedas a block in FIG. 3) processes the signal S received and, through apredetermined algorithm, compares the signal S with a reference signalcharacteristic of a required range within which the quantity 1 ofmaterial to be filled into the capsule body 2 must lie, using knownparameters such as, in particular, the size of the chamber 4. In theevent of deviation from this range, the control unit 18 appliescorrective output signals to the feeding and dosing station 7.

By checking the correctness of the predetermined quantity ofpharmaceutical material to be filled into each capsule body 2, thelinear transducer 5 checks the correctness of the weight of each capsuleC made by the machine 100.

As shown in FIG. 1, the carousel 15 is divided into a plurality ofslides 16 for supporting the capsule bodies 2, each slide 16 beingpositioned under the dose checking disc 11 and being synchronised withthe disc 11 itself.

The slides 16 have an upper horizontal surface 10 constituting theaforementioned contact elements 10, that is to say, the plate thatcloses the bottoms of the dosing chambers 4.

Further, each slide 16 is driven by radial drive means 17 between afirst, idle position in which the capsule bodies 2 are away from thechambers 4 of the plate 10 (see FIGS. 2 and 3), and a second, workingposition in which each capsule body 2 is positioned coaxially under arespective dosing chamber 4 in such a way that the quantity 1 ofpharmaceutical material can be transferred from the chamber 4 to therespective capsule body 2 during the horizontal movement of the slide 16in direction F (FIG. 4).

This step of actually transferring the quantity 1 into the capsule body2 is performed at a station 23 of the machine 100 located on thehandling line L upstream of the capsule C closing station 8.

The capsule filling machine 100 made in this way achieves theaforementioned aims thanks to the presence of the dose checking disc 11which comprises the chambers 4 in which the linear transducers 5operate: this permits a rapid and precise volumetric check to be carriedout on the quantity of pharmaceutical material before such quantity isactually placed in each capsule body 2. In other terms, the weight ofeach capsule C is checked by a simple and effective linear transducer inreal time during the process in which the solid pharmaceutical materialis actually filled into the capsules C, before the latter are closed.

It will be understood that the invention can be modified and adapted inseveral ways without thereby departing from the scope of the inventiveconcept. Moreover, all the details of the invention may be substitutedby technically equivalent elements.

1. A capsule filling machine for producing hard gelatin capsules of atype with lid and body containing a quantity of pharmaceutical material,the machine comprising a rotary turret or carousel which defines atleast one capsule handling line and on which the following arepositioned, one after the other: at least one station for feeding emptycapsules; at least one opening station where capsule bodies areseparated from lids to form two separate rows of capsule bodies andlids; at least one station for feeding and dosing the quantities ofpharmaceutical material to be filled into the capsule bodies; and atleast one station for closing the capsules by placing a lid over eachrespective body; wherein the machine further comprises volume transducerelement configured to generate a signal representative of a height ofthe pharmaceutical material placed in a dosing chamber, said signalbeing elaborated by a control and processing unit configured tocalculate a volume of the quantity of pharmaceutical material into thedosing chamber and to be inserted into the capsule bodies.
 2. Themachine according to claim 1, wherein the volume transducer elementcomprises elements for detecting the quantities of pharmaceuticalmaterial.
 3. A capsule filling machine according to claim 1 wherein thetransducer element comprises a sliding detector element drivenvertically and designed to enter the dosing chamber associated with thecarousel and designed to measure the height reached by the quantity ofpharmaceutical material in the respective dosing chamber.
 4. A capsulefilling machine according to claim 1, comprising a dose checking disccoupled with the carousel; the disc having made in it at least oneseries of dosing chambers of predetermined size, inside each of whichthe quantity of pharmaceutical material is temporarily placed; thevolume transducer element being designed to operate in the chambers. 5.The machine according to claim 4, wherein each chamber is designed to beclosed at the bottom by reciprocating contact elements moving towardsand away from the carousel.